FWIW...my Odroid N2 only has USB 3.0 ports on it and I can crank my Newpacs and R606 to the moon on it using the Gekko USB hub. Never once had an issue pop up and have run my 606 all the way up to 775MHz for a few days without cgminer tuning it down.

I'm currently running the R606 at 700MHz and 2 Newpacs at 500MHz. WU is at 100%.